1. The Field of the Invention
The present invention relates generally to digital connectors, such as may be used between audio or video components of a home entertainment system, as well as between components in a personal computing system.
2. Background and Relevant Art
Present consumer electronics are designed to store, process, and playback increasingly larger amounts of data. One reason for this is a present trend toward broadcasting, storing, and playing back digital audio and video signals. In particular, digital audio and video broadcasts are becoming more and more popular since they typically provide stark improvements in audio and visual clarity, compared with prior analog signals. Nevertheless, although digital signals were initially smaller than conventional analog signals, present technology now uses digital signals that hold greater and greater amounts of information, such that digital signals are now becoming quite large.
To accommodate the trend in digital data, conventional storage and playback devices have increasingly improved. For example, some present storage devices now include digital video discs (“DVD”) and high definition digital video discs (“HDDVD”), which are capable of storing several gigabytes or more of digital data. Other conventional storage devices include large hard drives that are implemented in a digital audio and/or video receiver, and which can store tens and hundreds of gigabytes of digital data. Conventional playback devices, such as for example, a digital audio receiver, or a digital television, such as a liquid crystal display (“LCD”), a plasma screen, and so forth, are also now also configured to process and playback the ever-expanding amounts of digital data.
Notwithstanding the improvements that digital-based storage and playback devices present over prior analog-based devices, conventional data transfer apparatus that link the broadcasting device or storage device to the playback device have reached their data carrying capacity in many cases. For example, common transfer speeds on conventional metal wiring ranges from 28 kilobits per second (kbps) to a few hundred megabits per second (mbps), and, in some cases, a few gigabits per second (gbps), depending on the transmission or reception protocol. A single digital video and audio signal sent to a digital television, however, might need to be transferred at a rate of several gigabits per second to be received and viewed properly. This can overwhelm a data transfer apparatus that may be used to carry multiple digital video and audio signals at once.
One reason that conventional data transfer apparatus are already close to their limits in terms of their abilities to transfer digital data is because conventional data transfer apparatus rely primarily on metal wiring. In particular, conventional metal wiring has a theoretical throughput limit of approximately 10 gbps to 20 gbps, which is near present data transfer needs—as many as 10 gbps in some cases. The reasons for these limits with metal wiring are based on a number of factors, such as signal attenuation, resistance, impedance, and so forth. In practice, however, most conventional metal connectors associated data transfer protocols are compatible with transfer rates of only a few gigabits per second, if that much. For example, conventional twisted-pair copper wiring has an approximate carrying capacity of about 1 gigabit per second. Coaxial cables, used to transmit television signals, also have similar throughput capacity, or possibly slightly more.
Accordingly, conventional cabling between electronic devices is becoming a limiting factor, despite the ever-improving storage and playback capabilities of the connected electronic devices. As a result, apparatus for transferring digital signals, particularly “High Definition” (“HD”) digital signals from one component to the next have also changed. In particular, the Digital Video Interface (“DVI”), High Definition Multimedia Interface (“HDMI”), and Universal Serial Bus (“USB”) interfaces and cables have been developed to more effectively transfer large volumes of digital data from one component to the next at a satisfactory throughput rate.
Unfortunately, DVI and HDMI cables also tend to be very expensive, are based on metal wiring, and are rather large and bulky, particularly if used for distances of more than a few feet. This can become a complication if a home user desires to wire one HD component in one room of a home to another room of a home. In particular, DVI and HDMI cables cannot be easily routed in a home at least in part since they have a stringent bend radius, and have other similar requirements that can complicate installation. Furthermore, the metallic composition of conventional DVI, HDMI, or even USB cables makes the cables susceptible to resistance, signal interference, and signal degradation, particularly over longer distances. As a result, despite the improved capabilities of present digital storage or playback devices, even DVI, HDMI, and USB connectors could limit the extent to which large digital data can be effectively transferred, and thus used.
As the demand for enhanced data transfer functionality has grown, attention has turned to various ways to circumvent metallic wiring between electrical components. For example, some wireless transfer protocols, such as the Blue Tooth protocol, Infrared Data Association (“IRDA”) protocols, HomeRF systems, and Wireless Ethernet Compatibility Alliance (“WECA”) protocols allow data to be transferred between components without using metallic wires for most of the distance.
Unfortunately, these types of systems still present various problems and shortcomings that may render them less than ideal for high throughput digital transfers. For example, infrared wireless networks depend on line-of-sight devices, and thus are not well suited for connecting devices that are located in different rooms, without strategic positioning of certain access points. In addition, HomeRF systems are characterized typically by relatively slow data rates, (about 1 mbps), have fairly limited range (about 75 to 125 feet), and can be difficult to integrate together within existing wired networks. Even still, the maximum data transfer speeds for other conventional wireless Ethernet networks is in the range of tens of megabits per second, rather than the gigabits per second necessary to transfer large digital content at an appropriate speed.
One way of circumventing some of the foregoing problems could be to substitute the copper wire in many of these conventional connector cables with optical fiber. In particular, a single mode optical fiber can carry approximately 20 terrabits per second (tbps), assuming a conventional 12.5 THz bandwidth, and a signal-to-noise value of about 20 decibels. This is a few orders of magnitude, and several thousand times the capacity of conventional copper wire. Unfortunately, the difficulty associated with precisely aligning optical fibers, and the lenses used within a relevant transmitter or receiver optical assembly, make conventional optical fibers less suitable for present consumer electronic applications. In particular, the manufacturing costs of aligning conventional optical components, such as an optical lens, at the appropriate fault tolerances between an optical fiber and a transmitter or receiver component would render conventional optical cables far too expensive for most consumer use.
In view of the foregoing, an advantage in the art could be realized with reliable, inexpensive connectors between home electronics components, which overcome the foregoing, and other, problems in the art. Ideally, such connectors should support high throughput speeds, while avoiding the signal interference and degadation inherent in transferring large digital files on copper wiring, and should be competitively priced.